The indoor fan motor error has occurred, and the indoor fan does not operate.
Turn OFF the power supply.
Is there any foreign matter that interferes the rotation of the line flow fan?
Yes
No
Remove the foreign matter and adjust the line flow fan.
Pay enough attention to the high voltage on the fan motor connector CN211.
Turn ON the power supply, wait 5 seconds or more, and then press EMERGENCY OPERATION switch.
Measure the supply voltage as follows within 12 seconds after EMER- GENCY OPERATION switch is pressed.
If more than 12 seconds passes, turn OFF the power supply and turn it ON again, then measure the voltage. *
<Indoor power P.C. board>
1. Measure the voltage between CN211 (+) and (–).
2. Measure the voltage between CN211 (+) and (–).
<Indoor electronic control P.C. board>
3. Measure the voltage between CN102 and GND (–).
*If more than 12 seconds pass after EMERGENCY OPERATION switch is pressed, the voltage measured at 2. above goes 0 V DC although the indoor P.C. board is normal.
Does the voltage between CN211 (+) and (–) on the power P.C. board rise to the range of 3 to 6 V DC within 12 seconds after EMERGENCY OPERATION switch is pressed?
Replace the indoor fan motor.
Yes
No
The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.
Measure the voltage between CN211 (+) and (–) while the fan motor is rotating.
Replace the indoor power P.C. board.
Is it unchanged holding 0
or 15 V DC? No
(Changed) Yes
(Unchanged)
Measure the voltage CN102 (+) and GND (–) on the indoor electronic control P.C board when the fan motor is rotating.
Replace the indoor fan motor.
Is there 325 V DC between CN211 (+)
and (–) ? Yes
Does the voltage between CN102 and GND (–) on the indoor electronic control P.C. board fall to 2 V or less within 12 seconds after EMERGENCY OPERATION switch is pressed?
Replace the indoor electronic control P.C. board.
No Yes
Replace the indoor power P.C.
board.
Is it unchanged holding 0
or 5 V DC? No
(Changed) Yes
(Unchanged)
Replace the indoor electronic control P.C.
board.
No
36
B Check of remote controller and indoor electronic control P.C. board
NOTE: Check if the remote controller is exclusive for this air conditioner.Does the unit operate with the remote controller?
OK Yes
No (Not clear)
Replace the batteries. (Refer to 10-1.4.) Press STOP/OPERATE (OFF/ON)
button on the remote controller.
Is LCD display on the remote controller visible?
Remove the batteries, then set them back and press RESET button.
(Refer to 10-1.4.)
Check if the unit operates with the remote controller.
Yes
No
Turn ON a radio to AM and press STOP/OPERATE (OFF/ON) button on the remote controller. *1
Is noise heard from radio?
Yes No Replace the remote controller.
Are there any fluorescent lights of inverter or rapid-start type within the range of 1 m? *2 Yes
No
• Reinstall the unit away from lights.
• Attach a filter on receiving part.
Replace the display and receiver P.C. board.
Assign a number of remote controller.
(Refer to 8-2.)
Check if the unit operates with the remote controller.
Does the unit operate with the remote controller?
Yes
No
OK
Measure the voltage between display and receiver P.C. board connector CN301 No.1(-) and No.2(+) when the remote controller button is pressed.
Is the voltage approximately 4 V DC - 5 V DC?
No
Yes Replace the indoor electronic control P.C. board.
*1 Look at the image of the signal transmitting section of the remote controller through the monitor of a digital camera or a camera phone. It is normal if the LED of the signal transmitting section lights up when the STOP/
OPERATE (OFF/ON) button on the remote control- ler is pressed. However, it may be difficult to see the illuminated LED of the signal transmitting section with a smartphone camera.
*2 If the inverter fluorescent light is turned on when the room is cool, the unit may have difficulty receiving the signal from the remote controller or may not be able to operate with it; if the inverter fluorescent light is turned on when the room is warm, the unit may be able to operate with the remote controller.
37
C Check of indoor P.C. board and indoor fan motor
Turn OFF the power supply.
Remove indoor fan motor connector CN211 from indoor power P.C. board and vane motor connector CN151 from the indoor electronic control P.C. board and turn ON the power supply.
Does the unit operate with the remote controller?
Does OPERATION INDICATOR lamp light up by pressing EMERGENCY OPERATION switch?
Yes No
Measure the resistance of indoor fan motor.
Refer to 10-5.
Short circuit:
Replace the indoor fan motor.
Turn OFF the power supply.
Check both “parts side” and “pattern side” of the indoor power P.C. board visually.
Replace the varistor (NR11) and fuse (F11). *3
Are the varistor (NR11) burnt and the fuse (F11)
blown? No
No Yes
Yes
Be sure to check both the fuse and the varistor in any case.
Is the fuse (F11) blown only?
Measure the resistance between CN211 (+) and (-) of indoor fan motor connector. *1, *2
Yes Is the resistance 1 MΩ or more?
Replace the fuse (F11) and the indoor fan motor. *3
No
Replace the fuse (F11). *3
No
No
Replace the indoor power P.C. board and the indoor fan motor.
Replace the indoor electronic control P.C. board.
Measure the resistance of the vane motor coil.
Refer to 10-5.
Short circuit:
Replace the vane motor and the indoor electronic control P.C. board.
*1. The fan motor connector's lead wire is red, whereas is black.
*2. Connect "+" of the tester to fan motor connector's lead wire, and “-” to lead wire, otherwise the resistance cannot be measured properly.
*3. Please replace the fuse after removing the indoor power P.C. board from the electrical box.
Is there approximately 5 V DC between 5 V (+) and GND (-) of the indoor electronic control P.C. board?
Is there approximately 12 V DC between 12 V (+) and GND (-) of the indoor electronic control P.C. board?
Are connector CN102 on the indoor electronic control P.C.
board or lead wires discon- nected?
Yes Replace the indoor fan motor.
Yes
Connect the connector or repair discon- nection.
No Yes Varistor
(NR11)
Indoor electronic control P.C. board
GND Fuse (F11)
CN211
Indoor power P.C. board
CN102
Measure the resistance of the i-see SENSOR MOTOR coil. Refer 10-5.
Short circuit
Replace the i-see SENSOR MOTOR and the indoor electronic P.C. board.
Measure the resistance of resistor (R111) [MSZ-LN18/25/35/60]/reactor (L112) [MSZ-LN50] on the indoor power P.C. board.
Is the resistance of resistor (R111) [MSZ-LN18/25/35/60]/reactor (L112) [MSZ-LN50] approximately 3.9 Ω?
R111 L112
38
D How to check miswiring and serial signal error
Turn OFF the power supply.
Is there rated voltage in the power supply?
Is serial signal error indicated 6 minutes later?
Yes No
No Check for incorrect indoor-outdoor connecting wiring.
Check the power supply.
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press EMERGENCY OPERATION switch.
Is there rated voltage between outdoor terminal block S1 and S2?
No Yes
Yes
Check for miswiring, broken wires, and loose wire connection between the power supply and outdoor terminal block S1 and between the power supply and outdoor terminal block S2.
• Reinstall either the unit or the light away from each other.
• Attach a filter on remote control receiving section of the indoor unit.
Wait for 2 or more minutes after the power supply is turned on.
Touch S2 and S3 with tester probes and start the emergency operation.
When the emergency operation starts, does the rated voltage occur for 2 seconds between indoor terminal block S2 and S3?
Turn the power supply OFF.
Turn the power supply ON.
Wait for 2 or more minutes after the power supply is turned ON. Touch CN202 and GND with tester probes and start the emergency operation.
During the emergency opera- tion, does DC (2V or less) occur for 2 seconds between CN202
and GND on the indoor power P.C. board?
No
Does the indoor POWER lamp blink continuously 6 minutes after the emergency operation starts?
No Does the outdoor LED light up?
Replace the indoor electronic control P.C. board.
Replace the indoor power P.C.
board.
Yes Yes
Yes
Does the outdoor LED blink 6 times?
Yes
Confirm that the thermostat is OFF and wiring is not loose.
No
Does DC (6 V or more) occur between indoor terminal block S2 and S3?
Yes
Replace the outdoor inverter P.C. board.*1 No
Turn the power supply OFF.
Replace the indoor power P.C.
board.
Start the emergency operation.
No
Yes
Repair completed.
Does DC (20 V or more) occur between indoor terminal block S2 and S3?
No Yes
Replace the outdoor inverter P.C. board.*1
Replace the indoor electronic control P.C. board.
*1 Electric charge may remain immediately after the power supply is turned OFF.
Perform the procedure after 3 minutes.
Replace the outdoor inverter P.C. board.*1
Turn the power supply ON.
Turn the power supply ON.
Does the indoor POWER lamp blink continuously 6 minutes after the emergency operation starts?
Yes
No
No No Was the indoor unit ever connected to the Multi (MXZ) series and operated (turned on)?
The connection information to the Multi series is stored in the indoor unit. Refer to “Deleting the memorized abnormal condition” described in 10-2.1 to clear the error history. When the error history is being cleared, the con- nection information also will be initialized. The indoor unit will be compatible with a low-standby-power model after initialization.
OK
Yes
MUZ Type
39
Turn OFF the power supply.
Is there rated voltage in the power supply?
Yes No
Turn ON the power supply.
Check the power supply.
Is there rated voltage between outdoor terminal block S1 and S2? No
Check the wiring.
Press EMERGENCY OPERATION switch once.
Does the indoor POWER lamp light up?
<Confirmation of the power to the indoor unit>
Does the LED on the outdoor control P.C. board repeat "3.6-second-OFF and 0.8-second-ON quick blinking"?
Is there amplitude of 10 to 20 VDC between outdoor terminal block S2 and S3?
<Confirmation of serial signal>
Is there any error of the indoor/
outdoor connecting wire, such as the damage of the wire, intermediate connection, poor contact to the terminal block?
Is there rated voltage between indoor terminal block S1 and S2?
<Confirmation of power voltage>
Yes
Yes Yes
Yes
Yes
No
No Is serial signal error indicated 6 minutes later?
Is serial signal error indicated 6 minutes later?
Yes
No
No
No
No
Yes No
(Lit or not lit)
Is there any miswiring, poor contact, or wire disconnection of the indoor/outdoor connect- ing wire?
Yes Correct them.
• Reinstall either the unit or the light away from each other.
• Attach a filter on remote control receiving section of the indoor unit.
No
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press EMERGENCY OPERATION switch.
• Turn OFF the power supply.
• Check once more if the indoor/outdoor connecting wire is not miswiring.
• Remove the indoor/outdoor connecting wire from outdoor terminal block S3.
• Short-circuit outdoor terminal block S2 and S3.*1
*1 Miswiring may damage indoor electronic control P.C. board during the operation.
Be sure to confirm the wiring is correct before the operation starts.
*2 Be careful of the residual voltage of smoothing capacitor.
Be sure to release the failure-mode recall function after checking.
LED indication
for communication status
Communication status is indicated by the LED.
Unit status
Blinking: Normal communication Lit: Abnormal communication or not connected
Pattern 1 and 2 is repeatedly displayed alternately. Each pattern is displayed for 10 seconds.
NOTE: "Lit" in the table below does not indicate abnormal communication.
Turn ON the power supply.
• Turn OFF the power supply.
• Remove the bridge between outdoor terminal block S2 and S3.
• Turn ON the power supply.
Yes
MXZ Type
Replace the indoor electronic control P.C. board.
Replace the outdoor control P.C. board. *2
Replace the indoor/outdoor connecting wire.
Outdoor control P.C. board
Blinking LED1 LED2 LED3
LED 1 LED 2 LED 3
Pattern 1 2 3
Unit B status Unit C status Unit A status
Unit D status Unit E status
Not lit Lit
Blinking
40
After performing the check, make sure to release the failure mode recall function.
Make sure that the front panel is firmly closed.
While pressing both OPERATION SELECT
button and TEMP + button on the remote controller at the same time, press RESET button.
First, release RESET button.
Hold down the other two buttons for another 3 seconds.
Make sure that the indicators on the LCD screen shown in the right figure are all displayed. Then release the buttons.
Press STOP/OPERATE (OFF/ON) button.
(the set temperature is displayed)
And press PURIFIER button once with the remote controller headed towards the indoor unit.*1
AIR PURIFYING operation is selected.
The AIR PURIFYING power operation check mode is set.
(Refer to 10-2.5.)
AIR PURIFYING power supply is normal.
Working of the interlock switch (Air purifying device) due to uncomplete close of the front panel could cause 2-time blink.
Abnormal discharge may occur due to much dirt on the air purifying device, clean it.
After cleaning, make sure to attach the air purifying device since it is completely dry.
If AIR PURIFYING power operation check is performed with the air purifying device wet, protection gets active and AIR PURIFYING lamp blinks continuously as well.
*2 Turn AIR PURIFYING power OFF and ON again.
(For turning OFF AIR PURIFYING power, refer to 10-2.3.)
(If it goes normal without turning OFF and ON, AIR PURIFYING lamp does not go OFF.)
Yes
No
No
Yes
Yes
No
12.5 V DC is generated.
Yes
No Replace the indoor electronic control P.C. board, after check of the wiring of CN1T1 on the indoor electronic control P.C. board.
High voltage (approximately 5.8kV) is generated during AIR PURIFYING power operation.
Pay careful attention and never touch the air purifying device and the high-voltage lead part.
Yes
No
OFF
Continuously blinking.
OFF
Continuously blinking.
Does AIR PURIFYING lamp blink 2-time with unit stopping?
Turn ON the power supply.
Replace the indoor electronic control P.C. board.
Remove the air purifying device,
firmly close the front panel, and then perform AIR PURIFYING power operation check (*2).
Does AIR PURIFYING lamp stay OFF, or continuously blink?
Does AIR PURIFYING lamp stay OFF, or continuously blink?
Turn OFF the power supply, and check the interlock switch (Air purifying device).
Is it firmly fixed?
Work and Not-work the interlock switch (Air purifying device) using something like a screw driver, and measure the resistance between CN1R1 and on the indoor electronic control P.C. board. Does the interlock switch (Air purifying device) function?
Keep the interlock switch
(Air purifying device) Not-work (close) using something like a screw driver.
Turn ON the power supply. Is the voltage between CN1T1 (+) and (GND) on the electronic control P.C. board) 0V with the unit stopping?
(Refer to 10-7.)
Set the AIR PURIFYING power failure mode recall function. (Refer to 10-2.2)
Replace the air purifying device.
Replace the indoor electronic control P.C. board.
When AIR PURIFYING power turns
ON by pressing PURIFIER button once, is there 12.5 V DC between CN1T1 (+) and (GND)?
Replace the interlock switch (Air purifying device).
Firmly fix the interlock switch (Air purifying device).
*1 Regardless of normal or abnormal condition, a short beep is emitted once the signal is received.